The levels of mercury detected in Taiji residents were above the national average, but further tests have found no ill effects, according to the National Institute for Minamata Disease. The tests it conducted involved hair samples from 1,137 of the town's approximately 3,500 residents.

"The results suggest there is a connection between hair mercury levels and eating cetaceans," the institute's director, Koji Okamoto, told reporters at the town hall.

Environmentalists have long protested against Taiji's dolphin slaughter and Japan's whaling activities and have taken up the mercury issue as part of their cause. Many cetaceans are at the top of their food chain, which makes their mercury levels higher because they accumulate it from all the fish lower in the food chain.

"If you're eating dolphin meat, you're eating poison, and if you're eating a lot of dolphin meat, you're eating a lot of poison," said Louis Psihoyos, the director of The Cove.

About 100 Taiji residents who gathered this morning at a town-hall meeting were told that there was no need for most of them to change their diet, although future tests are necessary.

The town council chief, Katsutoshi Mihara, rejoiced as he dipped raw slices of a striped dolphin into soy sauce.

"This may seem nonchalant, but I have absolutely no concerns, and I want to be able to keep my lifestyle," he said.

Mercury poisoning is a sensitive topic in Japan, where a disorder now called Minamata Disease was linked to a chemical company that dumped tonnes of mercury compounds on a southern island.

The disease causes spasms, sensory loss and limb malformations in newborns and can be fatal.